In the manufacture of steel, iron from blast furnaces is transported to steel making furnaces, commonly in so-called "bottle cars," which are railroad cars with specially constructed containers for holding molten metal. The railroad car carries an oval-shaped container called a "bottle" mounted for rotation about an axis parallel to the railroad car length. The bottle includes an opening in the top for receiving and dispensing the molten iron. To dispense or unload the iron, the bottle is rotated about its axis of rotation and the molten iron is poured into a receiving ladle that is then taken to a steel-making furnace. This dispensing or unloading takes place at a receiving station, where a railroad track extends over a pit in which the receiving ladle is located at a level beneath the track.
After the iron has been poured from the bottle car, a so-called "slag ladle" or "slag pot" is positioned in the pit adjacent the railroad car. The bottle is again rotated and slag material, which had been retained in the bottle when the iron was poured, is poured into the slag ladle. An alternative method for removing slag from the bottle is to rotate the bottle in an opposite direction about its axis away from the receiving ladle and dump the slag material into an area of the pit adjacent the iron-receiving ladle, and periodically cleaning the area. Another prior art technique involves pouring molten iron from the bottle at a receiving station and then transferring the bottle car to a slag pit for pouring off the slag that remains in the bottle car.
The prior art methods of removing molten iron from railroad bottle cars are unsatisfactory for several reasons. Due to the construction and arrangement of the railroad bottle car and the railroad tracks, a certain amount of molten iron is wasted in the sense of either being discarded or recycled. This is because it is necessary to rotate the bottle container substantialy 180.degree. from its original upright position to completely empty the bottle of molten iron. If the bottle is rotated to this extent, however, the railroad track above the receiving ladle is in the path of the flow and is contacted by the molten iron with resulting splashing and damage to the track. To avoid that, the bottles are rotated less than 180.degree. to keep the flow from the bottle opening to one side of the track. This prevents complete emptying and a certain amount of remaining iron is then lost, i.e., disposed of with the slag or returned with the car for refilling. Moreover, when it comes to removing the slag, the tracks over the slag pit or slag ladle are in the path of flow and become damaged by the slag and remaining iron emptied from the bottle. At regular intervals, slag and residual iron that is merely dumped in a pit must be removed at considerable expenditure of labor and equipment.